Routing system and method for double patterning technology

Abstract

A method includes receiving an identification of a plurality of circuit components to be included in an IC layout. Data are generated representing a first pattern to connect two of the circuit components. The first pattern has a plurality of segments. At least two of the segments have lengthwise directions perpendicular to each other. At least one pattern-free region is reserved adjacent to at least one of the at least two segments. Data are generated representing one or more additional patterns near the first pattern. None of the additional patterns is formed in the pattern-free region. The first pattern and the additional patterns form a double-patterning compliant set of patterns. The double-patterning compliant set of patterns are output to a machine readable storage medium to be read by a system for controlling a process to fabricate a pair of masks for patterning a semiconductor substrate using double patterning technology.

1. A routing method comprising steps of:
 (a) receiving in a processor an identification of a plurality of circuit components to be included in an integrated circuit (IC) layout; 
 (b) generating data within the processor representing a first pattern to connect two of the plurality of circuit components, the first pattern having a plurality of segments, such that at least two segments of the plurality of segments have lengthwise directions perpendicular to each other; 
 (c) reserving at least one pattern-free region, wider than a minimum spacing between parallel lines, adjacent to at least one segment of the at least two of the plurality of segments to prevent the processor from generating another pattern occupying or overlapping the at least one pattern-free region without increasing the minimum spacing throughout the entire IC layout; 
 (d) generating data within the processor representing one or more additional patterns near the first pattern, such that none of the one or more additional patterns is formed in the at least one pattern-free region, and the first pattern and the one or more additional patterns form a double-patterning compliant set of patterns; and 
 (e) outputting the double-patterning compliant set of patterns from the processor to a machine readable storage medium to be read by a system for controlling a process to fabricate a pair of masks for patterning a semiconductor substrate using double patterning technology. 
 
     
     
       2. The routing method of  claim 1 , wherein:
 step (b) is performed in such a way that at least one of the plurality of segments has a longer side and a shorter side, the shorter side having two corners; and 
 step (c) is performed in such a way that a longer side of the at least one pattern-free region abuts the shorter side of the at least one segment; and 
 the longer side of the at least one pattern-free region extends beyond both corners of the shorter side of the at least one segment. 
 
     
     
       3. The routing method of  claim 1 , wherein step (c) is performed in such a way that the at least one pattern free region is a rectangle, and a width of a shorter side of the at least one pattern free region is at least 2.1 times a minimum line spacing used between pairs of adjacent lines that are both oriented in a preferred direction of the IC layout. 
     
     
       4. The routing method of  claim 1 , wherein:
 step (b) is performed in such a way that the at least two segments form an angle, with a first segment of the at least two segments having a longer side thereof in a non-preferred direction of the IC layout and a second segment of the at least two segments having a longer side thereof in a preferred direction of the IC layout; and 
 step (c) is performed in such a way that a shorter side of the at least one pattern-free region abuts the longer side of the first segment; and 
 a longer side of the at least one pattern-free region abuts the longer side of the second segment and extends in the preferred direction beyond an end of the longer side of the second segment. 
 
     
     
       5. The routing method of  claim 4 , wherein step (c) is performed in such a way that the at least one pattern-free region extends away from the second segment at least as far as an end of the first segment that is furthest from the second segment. 
     
     
       6. The routing method of  claim 4 , wherein step (c) is performed in such a way that the at least one pattern-free region extends away from the second segment at least 2.1 times a minimum line spacing used between pairs of adjacent lines that are both oriented in the preferred direction of the IC layout. 
     
     
       7. The routing method of  claim 1 , wherein step (b) is performed in such a way that the at least two segments include respective turns between corresponding pairs of successive segments, and step (c) is performed in such a way that that the number of pattern-free regions reserved is equal to a number of turns. 
     
     
       8. The routing method of  claim 7 , wherein:
 the IC layout has a preferred direction and a non-preferred direction, and 
 step (c) is performed in such a way that a plurality of pattern-free regions are rectangles, each pattern-free region having a longer side abutting an adjacent one of the plurality of segments and extending in the preferred direction beyond an end of the abutting segment, each pattern-free region having shorter sides extending in the non-preferred direction. 
 
     
     
       9. The routing method of  claim 8 , wherein step (c) is performed in such a way that each pattern-free region has a width of at least 2.1 times a minimum line spacing used between pairs of adjacent lines that are both oriented in the preferred direction of the IC layout. 
     
     
       10. The routing method of  claim 8 , wherein step (b) is performed in such a way that the plurality of segments includes one or more non-preferred direction jogs connecting preferred direction segments, and step (c) is performed in such a way that, for each jog a respective pair of pattern free regions abuts the respective preferred direction segment on respective preferred direction edges thereof. 
     
     
       11. The routing method of  claim 1 , further comprising for a given area surrounded by additional patterns, providing an even number of spaces abutted by ones of the additional patterns too close to each other to be formed by a single mask, wherein the relatively close patterns include one of the group consisting of:
 at least one pattern having an end-to-end distance between two of the plurality of segments which are aligned with each other, 
 at least one pattern having an end-to-end distance between two of the additional patterns which are aligned with each other, and 
 at least one pattern having an end-to-end distance between one of the plurality of segments and one of the additional patterns aligned therewith, between 1 and 2.1 times a minimum line spacing used between pairs of adjacent lines that are both oriented in a preferred direction of the IC layout. 
 
     
     
       12. The routing method of  claim 1 , further comprising for a given area surrounded by additional patterns, providing an even number of spaces abutted by ones of the additional patterns too close to each other to be formed by a single mask, wherein the relatively close patterns include one of the group consisting of:
 at least one pattern having an end-to-run distance between two of the plurality of segments which are unconnected and perpendicular to each other, 
 at least one pattern having an end-to-run distance between two of the additional patterns which are unconnected and perpendicular to each other, and 
 at least one pattern having an end-to-run distance between one of the plurality of segments and one of the additional patterns which are unconnected and perpendicular to each other, to at least 2.1 times a minimum line spacing used between pairs of adjacent lines that are both oriented in a preferred direction of the IC layout. 
 
     
     
       13. The routing method of  claim 1 , further comprising for a given area surrounded by additional patterns, providing an even number of spaces abutted by ones of the additional patterns too close to each other to be formed by a single mask, wherein the relatively close patterns include one of the group consisting of:
 at least one pattern having a run-to-run distance between two of the plurality of segments which are parallel to each other and extend in a non-preferred direction of the IC layout, 
 at least one pattern having a run-to-run distance between two of the additional patterns which are parallel to each other and extend in the non-preferred direction, and 
 at least one pattern having a run-to-run distance between one of the plurality of segments and one of the additional patterns which are parallel to each other and extend in the non-preferred direction, to at least 1.6 times a minimum line spacing used between pairs of adjacent lines that are both oriented in a preferred direction of the IC layout. 
 
     
     
       14. The routing method of  claim 1 , further comprising for a given area surrounded by additional patterns, providing an even number of spaces abutted by ones of the additional patterns too close to each other to be formed by a single mask, wherein the relatively close patterns include one of the group consisting of:
 at least one pattern having a corner-to-corner distance between two of the plurality of segments which are unconnected and perpendicular to each other, 
 at least one pattern having a corner-to-corner distance between two of the additional patterns which are unconnected and perpendicular to each other, and 
 at least one pattern having a corner-to-corner distance between one of the plurality of segments and one of the additional patterns which are unconnected and perpendicular to each other, to at least 1.6 times a minimum line spacing used between pairs of adjacent lines that are both oriented in a preferred direction of the IC layout. 
 
     
     
       15. The routing method of  claim 1 , wherein at least one of the circuit components is a cell or macro block of a cell library, the circuit component having a plurality of pins, the method further comprising generating data representing a plurality of paths connecting respective pins inside the at least one circuit component with respective ones of the group consisting of:
 a segment from the first pattern generated in step (b), and 
 one of the plurality of additional patterns generated in step (d), 
 
       wherein the at least one path includes a via inside the circuit component. 
     
     
       16. The routing method of  claim 1 , wherein at least one of the circuit components is a cell or macro block of a cell library, the method further comprising generating data representing a plurality of paths connecting respective pins of the at least one circuit component with respective ones of the group consisting of:
 a segment from the first pattern generated in step (b), and 
 one of the plurality of additional patterns generated in step (d), 
 
       wherein:
 each of the plurality of paths has a segment directly connected to a respective pin; and 
 the directly connected segments of the plurality of paths are isolated from each other. 
 
     
     
       17. A routing method comprising:
 (a) receiving in a processor an identification of a plurality of circuit components to be included in an integrated circuit (IC) layout having a routing grid, a preferred direction and a non-preferred direction; 
 (b) generating within the processor data representing a first pattern to connect two of the plurality of circuit components, the first pattern having a plurality of segments, such that at least two of the segments extend along respective lines of the routing grid in the preferred direction and have respective ends connected by a single jog segment extending in the non-preferred direction, each jog segment spanning an odd number of lines of the routing grid of the IC layout; and 
 (c) generating within the processor data representing one or more additional patterns located on lines of the routing grid near the first pattern, such that the first pattern and the one or more additional patterns form a double-patterning compliant set of patterns; 
 (d) outputting from the processor the double-patterning compliant set of patterns to a machine readable storage medium to be read by a system for controlling a process to fabricate a pair of masks for patterning a semiconductor substrate using double patterning technology. 
 
     
     
       18. A system comprising:
 a computer readable storage medium storing data identifying a plurality of circuit components to be included in an integrated circuit (IC) layout; and 
 a processor coupled to the storage medium, embodying program instructions stored thereon, which when executed, configures the processor to perform steps comprising:
 generating data representing a first pattern to connect two of the plurality of circuit components, the first pattern having a plurality of segments, such that at least two segments of the plurality of segments have lengthwise directions perpendicular to each other; 
 reserving at least one pattern-free region, wider than a minimum spacing between parallel lines, adjacent to at least one segment of the at least two of the plurality of segments to prevent the processor from generating another pattern occupying or overlapping the at least one pattern-free region without increasing the minimum spacing throughout the entire IC layout; 
 generating data representing one or more additional patterns near the first pattern, such that none of the one or more additional patterns is formed in the at least one pattern-free region, and the first pattern and the one or more additional patterns form a double-patterning compliant set of patterns; and 
 outputting the double-patterning compliant set of patterns to a machine readable storage medium to be read by a system for controlling a process to fabricate a pair of masks for patterning a semiconductor substrate using double patterning technology. 
 
 
     
     
       19. A computer readable storage medium encoded with computer program code such that, when the computer program code is executed by a processor, the processor performs a routing method comprising:
 (a) receiving in the processor an identification of a plurality of circuit components to be included in an integrated circuit (IC) layout; 
 (b) generating within the processor data representing a first pattern to connect two of the plurality of circuit components, the first pattern having a plurality of segments, such that at least two segments of the plurality of segments have lengthwise directions perpendicular to each other; 
 (c) reserving at least one pattern-free region, wider than a minimum spacing between parallel lines, adjacent to at least one segment of the at least two of the plurality of segments to prevent the processor from generating another pattern occupying or overlapping the at least one pattern-free region without increasing the minimum spacing throughout the entire IC layout; 
 (d) generating within the processor data representing one or more additional patterns near the first pattern, such that none of the one or more additional patterns is formed in the at least one pattern-free region, and the first pattern and the one or more additional patterns form a double-patterning compliant set of patterns; and 
 (e) outputting from the processor the double-patterning compliant set of patterns to a machine readable storage medium to be read by a system for controlling a process to fabricate a pair of masks for patterning a semiconductor substrate using double patterning technology.